Torque wrench



Aug. 25, 1942 E. c. WORDEN TORQUE WRENCH Filed Sept. l0. '1940 Patented Aug. 25, 1942 UNITED STATES PATENT OFFICE TORQUE WRENCH Ernest C. Worden, East Norwalk, Conn., assignor to The Billings & Spencer Company, a corporation of Connecticut Application September 10, 1940, Serial No. 356,201

Claims. (Cl. 64-29) also improved valve means carried by one of the parts of the piston, and improved cam means and spring means disposed Yin an improved relation to the parts of the improved piston, while also providing an improved casing wherein the several parts of the mechanism are enclosed. Other objects of my invention include the provision of such an improved construction whereby manufactureis substantially facilitated and whereby it is made possible to produce a wrench which will function uniformlybdespite variations in alignment of the parts and enablinguthe structure to be inexpensively produced, while also functioning satisfactorily over long periods and minimizing wear and enabling ready replacement of worn parts to be effected. These and other objects and advantages of my improved construction will, however, hereinafter more fully appear. a

In the accompanying drawing, I have shown for purposes of illustration two embodiments which my invention may assume in practice.

In this drawing:

Figure 1 is a side elevation of my improved wrench in use and operated by a suitable motor driven device;

Fig. 2 is a top plan view of the wrench;

Fig. 3 is a side elevation of the same, portions bf the casing being shown in section to facilitate illustration and the operating mechanism being shown in its normal position;

Fig. 4 is a central vertical vsection on line 4-4 of Figure 2, the operating parts being shown in their position occupied at the limit of tightening and as they are about to release;

Fig. 5 is a transverse section on line 5-5 of Figure 4;

Fig. 6 is a transverse section on line 6 6 of Figure 4; I

Fig. 7 is a transverse section on the same line, but looking in the opposite direction as indicated at 'I'I;

Fig. 8 is a perspective view of the main part of the piston, and

Fig. 9 is a detail view of the lower part of the in Figure l'my improved wrench unit, generally indicated at l, having oppositely directed turning elements 2 and 3 on its opposite vends and respectively connected by adapters 4 and 5 to any usual electric motor operated actuator mechanism 6 and to the work, herein a bolt head ornut 'I; the wrench unit I herein being of improved construction as hereinafter more fully described. A

Referring more particularly to this unit I, it will be observed that it .includes an improved casing comprising cooperating casing members 8 and 9. Of these, the member 8 forms a cylinder I0 for an improved piston,` generally indicated at II, and hereinafter moref specically described, while the casing member 9 forms a cover for this cylinder while also being provided with anl axial bore I2 through which the piston rod moves. As shown,'the casingl member 8 '1s also provided with a raised axial extension or projection I3 above its bottom and has a nut I4 closing a centrally disposed filling aperture Ma in the top ofA this extension. Herein the top of the latter is also preferably bevelled around this nut as illustrated at I5, and a rectangular, herein squared, socket I6 is also provided on 'this extension to receive any suitable turning portion as, for example, a. projecting squared end on the adapter 5. Attention here is also directed to the fact that the opposite end of the member 8 is suitably internally threaded as at I'l and has the cover member `9 threaded into the same. This cover is also provided with an elongated inwardly extending and externally bevelled bearing portion I8 for the piston rod and also carries suitable .the filling aperture Ida which is of suicient operating mechanism showing a modified form4 of spring therein.

diameter also to function as a vent and is conveniently disposed and accessible through the compactly disposed turning socket I5.

Disposed in this casing and cooperating therewith is the improved piston mechanism I I. This mechanism herein includes a sleeve portion 2| snugly fitting the walls ofthe cylinder I0 and having a narrow inwardly turned annular flange 22 on its upper end. The surface of this flange 22 adjacent the bottom of the cylinder I0 also engages a coiled spring 23 acting between the bottom of the cylinder and this ange and normally In`this illustrative construction, I have shown tending t0 maintain the Sleeve 2| in the POSiIiOD illustrated in Figure 3, while enabling this sleeve 2| to be compressed into the position shown in Figure 4. Engaging the upper face ofthe flange 22 is also a cooperating portion 24 ofthe piston herein a cylindrical disc-like portion of smaller diameter than the sleeve 2| and having a fiat bottom surface engaging a like fiat top surface on the flange 22 and on` the sleeve 2|, these surfaces being preferably ground and lapped together to provide a perfect seat, herein indicated at 25. As shown, the portion 24 of the piston also has a piston rod 26formed integral therewith and projecting therefrom in the opposite direction from the sleeve 2| and spring 23 and through the bearing I8 and packing |9 on the cover 9. Thus, it will be observed that even should the piston rod 26 be out of line with the sleeve 2| as, for example, if the cover 9 is not in exact alignment with the sleeve 2| or with the casing member 8, .no difficulty is experienced since the portion 24 may locate itself as necessary eccentrically relative to the flange 2 2 on this sleeve without conflict with the wall of the cylinder I0. Here attention is also directed to the fact that the spring 23 acting through the flange 22 also normally acts to maintain the latter in contact with the under surface of the piston portion 24.-

Cooperating with this piston is also improved oil flow controlling mechanism. Herein, the under surface of the piston portion 24 is suitably annularly recessed, as shown at 21, onV diametrically opposite sides of the stem 26, and these recessed portions are provided with ports 28 in the tops thereof. These ports 28 are controlled by balls 29 in turn controlled by arcuate spring wire holding members Y3|! suitably fixed at one end, as at 3|, to the under-side of the portion 24 and having rounded cup shaped ends 32 normally pressing the balls 29 against seats on the lower ends of p the ports 28. Further, it will be observed that the piston rod 26 is provided with an axial aperture 33 `in its lower end opening into an axial larger tion 24 of the piston. Herein, the spring 36 acts at its opposite end against an adjustable abutment 38 in the upper end of the chamber 34, while an I outer closure or seal is provided by an outer nut 38a of larger diameter threaded into the upper end of the chamber 34. Thus, it will be observed that both the action and location of the balls and their cooperating springs are reversed as compared with my prior structure,while eliminating all need for an expensive stem type valve and utilizing an vinexpensive ball valve. It is also made possible to obtain a better seat, while when a predetermined torque controlled by thc oil flow ccntrolling mechanism is exceeded. Herein, these means are also of an improved construction and in an improved location. As shown, they include upwardly projecting hardened cam pins 381) driven into and projecting above the piston portion 24; these pins herein being diametrically oppositely located, as illustrated, and disposed in planes at right angles to the ports 28 and also having oppositely disposed inclined upper faces 39 and end abutments 40. Herein these cam members '-ooperate with cooperating hardened cam members 4| of similar shape and having similar sloping faces 42 and abutments 43 but depending at spaced points around and formed integral with an upper cam carrying ring member 44. Herein this member 44 is also provided with a central beveled aperture 45 adapted to receivethe beveled bearing |8,`while being maintained spaced from-the latter due to engagement loi" the cover 9 with the top of the ring 44. Further, it will be vobserved that the ring 44 is suitably attached, as by suitable screws 46 extending through the side walls of the upper"` end ofthe casing member 8 below the threads thereon into which the cover 9 is threaded, while cooper` ating annular sealing shoulders 41 are also provided on this. ring and the'casing 8 below these screws 46. Thus, it is made possible to eliminate all necessity for providing, as in my prior construction, cams which are carried by the casing in the bottom of the cylinder wherev it isdiflicult and expensive to form the same during manu-` facture. It is also made possible to provide these cams on readily accessible surfaces of a ring member which may be much less expensively produced and also may be readily hardened. Also, it will be observed that this ring member may be readily removed to permit access to or removal of otherparts, while it can also be replaced in the event of wear at a fraction of the expense necessary to replace the main casing, as in my prior construcsloping surfaces 39 on the piston against the cooperating sloping surfaces 42 on the ring 44 fixed to the casing 8. This rotation will be continued so long as the torque does not exceed the predetermined maximum determined by the setting of the oil flow controlling mechanism. When, however, such a maximum is exceeded, the cam surfaces 42, 39 will slip and, the piston portion. 24 then moving downward, the pressure will build up in the lower end of the cylinder l0, herein for convenience indicated as the space 48, sufficiently to force up the ball 31 and permit the liquid to flow up through the ports 33, 31a, into the top of the cylinder ID, which herein for convenience is indicated as the space 49. Accordingly, the pressure in the two spaces 48 and 49 will tend to equalize .and as a result, the entire piston including the portion 24 and sleeve 2| will tend to move down in such manner as to cause the surfaces 42 and 39 to disengage when the parts are approximately in the position illustrated in Figure 4. When, however, the pressure equalizes in the spaces 48 and 49, the valve 31 will close automatically at substantially the same time that the cam surfaces 42, 3S pass out of contact with one another anglarly. Then, the spring 23 will also act automatically'and press the piston Il toward the cover 9 and this movementl ofthe piston will automatically open the ball valves 29 so that the oil will flow through the ports 28 to bring the ports back into the position shown in Figure 3, wherein the parts of the wrench are again connected ready for use. Obviously, this disconnection and reconnection of the parts will continue so long as the predetermined torque is exceeded, in such manner as to make the wrench inoperative beyond the predetermined pressure limit for which the same is set by the selected adjustmnt of the spring 36 which may be varied as desired. Further, it will beevident that the parts will be automatically released if too great pressure is applied to the member 2. Also, when the direction of rotation is reversed, \a positive.

drive will be produced by the engagement of the abutments 40 and 43.

In Figure 9, a modified construction Vis illustrated wherein, instead of a cylindrical spring 23, a conical or telescoping'type of spring 50 is provided which is adapted to atten when compressed. Obviously, ,the operation of the mechanism equipped with such a spring will be essentially similar to that heretofore described.

While I have herein specifically described two forms which my invention may assume in pracdiameter than said first mentioned portion, and

spring means acting between said sleeve and the opposite end of said cylinder for maintaining said cooperating means in frictional engagement.

4. In a fluid controlled torque wrench, cooperating casing and piston elements having turning means thereon and also including a fluid containing cylinder and a plurality of separate' piston forming portions engagingfin said cylinder, valve means on one of said portions controlling the ow of fluid between opposite sides of said portions, cooperating driving lug means on one of said portions and on said casing disposed in one end of said cylinder for transmitting torque between said turning means, spring means acting between the other of said portions and the op- `posite end of said cylinder and cooperating with said valve means fory maintaining said vcooperating means in engagement, and means removably mounted in the rst mentioned end of said cylinder and carrying the lugv means disposed' therein. l

5. In a torque wrench, cooperating casing and piston elements having turning means thereon and also including a cylinder and a plurality of separate piston forming portions engaging in said cylinder, cooperating driving lug means on tice, it will be understood-that these forms have been shown for purposes of illustration, and that the invention may be modified and embodied in other forms witho'ut departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a fluid controlled torque wrench, cooperating casing and piston elements having turning means thereon and also including a fluid containing cylinder and a plurality of separate pis- `ton forming portions engaging in said cylinder,

valve means on one, of said portions controlling the flow of fluid between opposite sides of said portions, cooperating frictionally engageable drive means on one of said portions and on said casing in one end of said cylinder for transmitting torque between saidl turning means, and spring means acting between the other of said portions and the opposite end of said cylinder and cooperating :with said valve means for maintaining said cooperating means in frictional enggement.

2. In a torque wrench, cooperating casing and piston elementsI having turning means f thereon and also including aV cylinder and cooperating separate piston forming portions engaging in said cylinder, one fitting the cylinder walls and the other of smaller diameter, cooperating frictionally engageable drive means on said last mentioned portion and on said casing in one end Aof said cylinder for transmitting torque between said turning means, and spring means acting b'etween the rst mentioned portion and the opposite end of said cylinder for maintaining said cooperating means in frictional engagement.

3. In a torque wrench, cooperating casing and piston elements having turning means thereon and also including a cylinder and a plurality of separate piston forming portions engaging in said cylinder, cooperating frictionally engageable drive means on oneof said portions and on said casing in one end of said cylinder for transmitting torque between said turning means, the other of said portions comprising a sleeve of larger one of said portions and on said casing disposed in` one end of said cylinder for transmitting torque between said turning means, spring means acting between the otherl of said portions and the opposite end of said cylinder for maintaining said ,cooperating means in engagement, and means removably mounted in the first mentioned end of said cylinder and carrying the lug means disposed therein, said first mentioned portion having a piston rod thereon carrying one of said turning means and said lug carrying means comprising a ring through which said rodv projects.

6. In a torque wrench, cooperating casing and piston elements including a cylinder and a plurality of separate piston forming portions engaging in said cylinder, cooperating driving lug means on one of said portions and on said casing disposed in one end of said cylinder for transmitting torque between said turning means, and spring means acting between the other of said portions and the opposite end of said cylinder for maintaining said cooperating means in en.- gagement, said lug carrying portion of said piston having a turning member rotatable therewith and projecting through one end of said cylinder and the other end of said cylinder having an axial turning member soc ket surrounded by said spring means.

'7. In a liquid controlled torque wrench, cooperating casing and piston elements including a cylinder and a plurality yof engaging piston forming portions in said cylinder for dividing said cylinder'into two chambers adapted to contain liquid, cooperating driving lug means on one of said portions and on said casing disposed in one end of said cylinder for transmitting torque between said turning means, valve means on said last mentioned portion controlling the flow of liquid between said chambers, and spring means acting between the other of said portions andthe opposite end of said cylinder and cooperating with said valve means for maintaining said cooperathaving a turning socket therein and an axial filling aperture in said socket communicating with said cylinder.

8. Ina torque wrench, cooperating casing and piston elements having' turning means thereon and also including a cylinder and a plurality of engaging piston forming portions in said cylinder, cooperating driving lug means on one of said portions and on said casing disposed in one end of said cylinder for transmitting torque between said turning means, and spring means acting between the other of said portions and the opposite end of said cylinder for maintaining said cooperating means in engagement, said casing having a cover threaded in one end thereof and said rst mentioned piston portion havingl a rod journalled in said cover and said lug means in the rst mentioned end of said cylinder being carried on a sealing ring between the cylinder and the cover threads. Y

9. In a uid controlled torque wrench, cooperating casing and piston elements having turning means thereon and also including a fluid containing cylinder and a plurality o separate piston forming portions engaging in said cylinder and dividing said cylinder into two fluid containing chambers, cooperating frictionally engageable drive means on one of said portions and on said casing in one end of said cylinder for transmitting torque between said turning means,

springl means acting between the other of said portions and the opposite end of said cylinder and cooperating with said valve means for maintaining said cooperating means in engagement, and valve means carried by said first mentioned portion controlling the iiowof iiuid to opposite sides of said portion when said frictional drive means slip.

10. Ina iiuid controlled torque Wrench, cooperating casing and piston elements having turning means thereon and also including a uid containing cylinder and a plurality of separate piston forming portions engaging in said cylinder and dividing said cylinder in'to two fluid containing chambers, cooperating frictionally engageil able drive means on one of said portions and on said casing in one end of said cylinder for transmitting torque between said turning means, spring means acting between the other of said portions and the opposite end of said cylinder and cooperating with said valve means for maintaining said cooperating means in engagement, and valve means carried by said rst mentioned portion controlling vthe ow of fluid to opposite sides of said portion when said frictional drive means slip and including oppositely moving ball valves and cooperating port means controlling the ow to opposite sides of said piston portion.

ERNEST C. WORDEN. 

